Connective tissue content of skeletal muscle plays a key role in meat quality. Previous pilot studies carried out in our lab have indicated that the smallest littermate may have a higher proportion of connective tissue in skeletal muscle (Clelland A., 2001). Connective tissue provides a structure to the muscle belly and is composed of ground substance, fibres and connective tissue cells. A proportion of these three elements of the connective tissue comprise of collagen I and fat deposits. This is an important concept to the meat industry as an increased amount of these components can increase meat toughness and intramuscular fat respectively, both having an impact on the resultant meat quality. The primary objective of this study is to investigate the relationship between undernutrition, collagen and fat content using a naturally occurring model. In the pig, it can be argued that differing levels of nutrition received, in utero, are a major cause of intra-litter variation. Therefore the smallest and largest littermates were chosen and content of collagen I and fat deposition were analysed in the M. semitendinosus of both.